| Augmented cyclooxygenase-2 effects on renal function during varying states of angiotensin II. | |
| | |
MedLine Citation:
|
PMID: 20668099 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Nonsteroidal anti-inflammatory drug usage has long revealed renoprotective prostaglandin actions on the renal microvasculature during increased pressor hormone influence, but whether increased cyclooxygenase (COX)-2 expression supports prostaglandin vasodilatory influence by interfering with the actions of ANG II remains unresolved. Therefore, we tested the hypothesis that COX-2 inhibition causes hemodynamic and excretory effects that are increased in proportion to ANG II activity. In anesthetized Sprague-Dawley rats having augmented cortical COX-2 expression but different ANG II activity, we conducted renal clearance experiments during acute inhibition of COX-2 with nimesulide (NMSLD) and inhibition of COX-1 with SC-560. In one series of experiments, acute captopril [acute angiotensin-converting enzyme (ACE) inhibitor (aACEi)] was administered alone (n = 13) or in combination with chronic captopril [chronic ACEi (cACEi)] pretreatment (n = 19). In another series of experiments, rats were fed a normal-sodium [0.4% (NS), n = 12] or a low-sodium [0.03% (LS), n = 18] diet. NMSLD did not alter mean arterial blood pressure in any group but, in the LS and cACEi groups, decreased renal plasma flow (from 3.99 ± 0.33 to 2.85 ± 0.26 and from 4.30 ± 0.19 to 3.22 ± 0.21 ml·min(-1)·g(-1)), cortical blood flow (-12 ± 8% and -13 ± 4%), and glomerular filtration rate (from 0.88 ± 0.04 to 0.65 ± 0.05 and from 0.95 ± 0.07 to 0.70 ± 0.05 ml·min(-1)·g(-1)). In contrast, medullary blood flow (MBF) was significantly decreased by COX-2 inhibition in NS (-24 ± 5%), LS (-27 ± 8%), aACEi (-16 ± 3.8%), and cACEi (-24 ± 4.2%) groups. Absolute and fractional sodium excretion rates were unchanged by NMSLD, except in the LS group (0.75 ± 0.05 μeq/min and 0.43 ± 0.15% and 0.51 ± 0.06 μeq/min and 0.26 ± 0.10%). SC-560 did not augment the effects of NMSLD. These results demonstrate an augmented COX-2-mediated vasodilation that is not contingent on ANG II, in contrast to COX-2-mediated augmented sodium excretion, where ANG II activity is requisite. Furthermore, the COX-2 effects on MBF are not contingent on ANG II or changes in cortical microvascular responses. These results reflect COX-2 continual regulation of MBF and adaptive opposition to ANG II prohypertensinogenic effects on renal plasma flow, cortical blood flow, glomerular filtration rate, and absolute and fractional sodium excretion. |
| | |
Authors:
|
Torrance Green; Jorge Rodriguez; L Gabriel Navar |
Related Documents
:
|
7436089 - Determining time of death of a dog by analyzing blood, cerebrospinal fluid, and vitreou... 9553239 - Low-flow anesthesia in adult orthotopic liver transplantation: a preliminary clinical e... 11438059 - Theoretical investigation of the role of choriocapillaris blood flow in treatment of su... |
Publication Detail:
|
Type: Editorial Date: 2010-07-28 |
Journal Detail:
|
Title: American journal of physiology. Renal physiology Volume: 299 ISSN: 1522-1466 ISO Abbreviation: Am. J. Physiol. Renal Physiol. Publication Date: 2010 Nov |
Date Detail:
|
Created Date: 2010-11-04 Completed Date: 2010-12-02 Revised Date: 2011-11-01 |
Medline Journal Info:
|
Nlm Unique ID: 100901990 Medline TA: Am J Physiol Renal Physiol Country: United States |
Other Details:
|
Languages: eng Pagination: F954-62 Citation Subset: IM |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
Angiotensin II
/
physiology* Angiotensin-Converting Enzyme Inhibitors / pharmacology Animals Blood Pressure / physiology Cyclooxygenase 1 / physiology Cyclooxygenase 2 / physiology* Cyclooxygenase 2 Inhibitors / pharmacology Cyclooxygenase Inhibitors / pharmacology Glomerular Filtration Rate Immunohistochemistry Kidney / enzymology*, physiology* Kidney Cortex / enzymology Male Rats Rats, Sprague-Dawley Renal Circulation / physiology Sodium / metabolism, urine |
| Chemical | |
Reg. No./Substance:
|
0/Angiotensin-Converting Enzyme Inhibitors; 0/Cyclooxygenase 2 Inhibitors; 0/Cyclooxygenase Inhibitors; 11128-99-7/Angiotensin II; 7440-23-5/Sodium; EC 1.14.99.1/Cyclooxygenase 1; EC 1.14.99.1/Cyclooxygenase 2 |
| Comments/Corrections | |
Comment In:
|
Am J Physiol Renal Physiol. 2010 Nov;299(5):F952-3
[PMID:
20826572
]
|
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Cell-cell contact regulates gene expression in CDK4-transformed mouse podocytes.
Next Document: Increased renal phosphodiesterase-5 activity mediates the blunted natriuretic response to a nitric o...